1. Field of the Invention
The present invention relates to a hearing prosthesis and, more particularly, a transformable speech processor module for a hearing prosthesis.
2. Related Art
The use of medical devices to provide therapy to individuals for various medical conditions has become more widespread as the advantages and benefits of such devices become more widely appreciated and accepted throughout the population. In particular, devices such as implantable pacemakers, defibrillators, functional electrical stimulation devices such as hearing prostheses, organ assist or replacement devices, and other medical devices, have been successful in performing life saving and/or lifestyle enhancement functions for a number of individuals.
Many such medical devices often include one or more sensors, processors, controllers or other functional electrical components that are permanently or temporarily implanted in a patient. Many such implantable devices require the transcutaneous transfer of power and/or information with external components that are part of, or operate in conjunction with, the implanted components of the medical device. Such external components are typically removably attached to the body of the patient.
One such type of medical device is a cochlear implant system, also commonly referred to as a cochlear prosthesis. Cochlear implant systems provide the benefit of hearing to individuals suffering from severe to profound hearing loss. Hearing loss in such individuals is due to the absence or destruction of the hair cells in the cochlea which transduce acoustic signals into nerve impulses. Cochlear implants essentially simulate the cochlear hair cells by directly delivering electrical stimulation to the auditory nerve fibers. This causes the brain to perceive a hearing sensation resembling the natural hearing sensation normally delivered to the auditory nerve.
Conventional cochlear implant systems primarily include an external assembly directly or indirectly attached to the body of the patient (referred to herein as the recipient), and an internal assembly which is implanted in the patient. The external assembly typically comprises one or more microphones for detecting sound, a speech processing unit that converts detected sound, particularly speech, into an electrical coded signal, a power source, and an external transcutaneous transfer coil. The internal assembly typically comprises an internal transcutaneous transfer coil, a stimulator unit located within a recess of the temporal bone of the recipient, and an electrode array positioned in the recipient's cochlear.
Collectively, the external coil and the internal coil form an inductively-coupled transcutaneous transfer system. The transfer of energy via this system is controlled to effect the transmission of the electrical coded signals, referred to herein as stimulation signals, and power signals from the external speech processing unit to the implanted stimulator unit. Similarly, the transcutaneous transfer system may be used to effect the transmission of telemetry data from the implanted stimulator unit to the exterior speech processing unit. Conventionally, the communications link has been in the form of a radio frequency (RF) link, although other such links have been proposed and implemented. Once a stimulation signal has been transmitted to the implanted transcutaneous transfer coil, it is provided to the implanted stimulator unit which processes the signal and outputs one or more signals to the intra-cochlear electrode assembly which applies the electrical stimulation directly to the auditory nerve of the recipient.
The speech processor unit has traditionally been worn on the body, such as by being attached to clothing, or by being supported on the ear of the recipient. This latter configuration is commonly referred to as a BTE (behind the ear) configuration. The speech processor unit is relatively expensive and susceptible to damage, especially in the hands of infants or small children, or when used in an unsuitable environment.